Ullage rod for internal combustion engines and the like



J. CORNELL April 5, 1955 ULLAGE ROD FOR INTERNAL COMBUSTION ENGINES AND THE LIKE Filed June 2, 1952 INVENTOR. flea} Corin /Z United States Patent ULLAGE ROD FOR INTERNAL COMBUSTION ENGINES AND THE LIKE Jacob Cornell, Huntington Woods, Mich., assignor to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Application June 2, 1952, Serial No. 291,187

9 Claims. (Cl. 33--126.7)

This invention relates to oil gauges and the like. It particularly concerns ullage rods for testing and determining the oil level in oil reservoirs of internal combustion engines, especially V engines.

A difficulty encountered with conventional ullage rods, sometimes called dip sticks, has been the inability to always remove the blades of these rods from the crankcase and tubular sheath provided therefor without obtaining an oil smear or other disturbance of the oil film within the reading indicating area of the blade. When this occurs a satisfactory determination of oil level is usually impossible.

In actual practice, it is the custom to remove the rod from its tubular sheath, wipe it clean, replace it and remove it a second time to take the reading. The blade is conventionally of flat strip character and somewhat narrower than the sheath, and in removing it from the passage for taking a reading, the blade readily assumes a close chordal relationship with the passage wall thus permitting the edge portions of the blade to rub against such wall. If the surface or face of the blade immediately adjacent the contacted wall surface of the passage is the reading face, it is possible for this face to pick up oil from the adjacent wetted surface of the passage which will produce a smear at the reading surface which will either prevent an oil level reading or cause an inaccurate one when the blade is removed. Moreover, in withdrawing the blade, the condition of the oil film at the reading surface may be disturbed by the rubbing contact made as above described with the wall of the passage and also contribute to an inaccurate reading.

When the aforesaid difficulty occurs, it becomes necessary to again wipe the stick clean and take a new read ing. It is generally found, however, that once a smear has been obtained, it is thereafter difficult to obtain an accurate reading, for further smears will occur.

The foregoing conditions are especially encountered when the passageway from the outlet to the oil reservoir is of a single or double curved character, as in V engines of current manufacture. This requires the blade of the normally straight ullage rod to .be fiexed in conforming to the lengthwise curvature of the passage and to bear against the surface portion of the passage adjacent the outer side of the curved blade. Considerable contact with the wall of the passage results from this action and accentuates the smear possibilities. Moreover, irregulatities in the flatness of the blade produced durlng handling, or curvature produced as a result of permanent set in the shape of the blade by repeated action in a curved passage, also contribute to the aforesaid possibility of obtaining an inaccurate reading or no reading at all.

Much difficulty has also been encountered in reading conventional ullage rods because the indicating surface is bright or substantialy so. When the oil film overlies such a surface it is difficult against this background to locate the upper limit of the film and make a depth reading without considerable maneuvering of the rod.

I have discovered that the aforesaid smearing or other disturbances of the oil film in the reading area of the ullage rod may be substantially overcome by providing upon the blade face of the rod adjacent the reading indicia thereon and preferably adjacent each limit of the reading area, a protuberance or other generally preferably narrow raised transverse portion which substantially projects outwardly away from the reading face of the blade. These projections will, during removal of the rod, substantially prevent contact of any portion of the reading surface of the blade with the passageway and prevent any smearing of the oil film on the reading face by 1nh1b1ting contact of the passage therewith and by preventing its pickup of oil from surrounding wetted surfaces. A pair of projections straddling the reading area 18 preferred as such an arrangement assures complete freedom from the problem. This is especially true where the passageway is of a curved character as in conventional V engines and where in handling the ullage rod it becomes somewhat deformed from a straight shape.

I have further discovered that the ability to read the oil level on the indicating surface of the ullage rod may be markedly improved by providing this indicating area with a dull or preferably black-appearing surface. This background for the oil film on the reading surface renders the edge of the film more readily visible and permits a quick reading to be made.

An object of my invention is accordingly to provide an ullage rod or dip stick having a construction that will facilitate the obtaining of a clear and accurate reading of the oil supply of an engine.

Another object of my invention is to provide an ullage rod or dip stick capable of insertion in and removal from a tubular passage or sheathing connecting with the oil reservoir, without producing oil smears on or otherwise disturbing the oil film on the indicating surface area of the rod.

An additional object is to provide an oil gauge of simple construction for automotive vehicles and the like which is provided adjacent the oil level indicating area of the rod with oil-smear-preventing means facilitating the taking of clear and accurate initial readings.

A further object is to provide an oil gauge or ullage rod having an oil level indicating surface area treated to render the oil film thereon especially the upper edge thereof readily visible.

These and other objects of my invention will appear from the following description wherein I have for the purposes of illustration and not limitation shown my invention as applied to a V engine of current manufacture.

In the drawing wherein similar reference numerals indicate like or corersponding parts:

Figure 1 is an elevational view showing the ullage rod of my invention in position on a V engine having a curved tubular sheathing for the rod, a portion of the engine crankcase and oil reservoir being shown in section to show the positioning of the measuring end of the rod in the oil pp y;

Figure 2 is an enlarged view of a portion of Figure 1;

Figure 3 is an elevational view of the ullage rod of my invention when removed from its sheathing;

Figure 4 is an enlarged perspective view of the gauge end of the ullage rod of my invention showing the oil level indicia surface provided with a blackened background against which to read the oil .level and showing a pair of smear inhibiting crimps juxtaposed the upper and lower limits of the reading area;

Figure 5 is an enlarged view on the indicating end of the ullage rod of my invention located in a curved passage during removal therefrom for reading purposes; and

Figure 6 is a cross sectional view taken at 5-5 of Figure 5.

Referring now to the drawing, the numeral 10 generally represents the crankcase of a V-8 engine of current production having a cylinder block 12 and an oil reservoir 14 enclosed by a pan 16.

A vertical bore or passage 18 extends downwardly from an exterior point 19 on the block 12 and opens into the oil reservoir 14. An ullage rod or dip stick 20 is positioned in the passage 18 and oil revervoir 14 in which position it is supported by an elongated sheathing or casing member 22 through which the rod 20 extends and is guided to the reservoir 14. The: sheathing member 22 is preferably a tube of circular section and, as seen in Figure 1, this tube curves outwardly from the point 19 of the cylinder block and terminates adjacent the cylinder head 24 where it is supported by a bracket 25. The tube 22 moreover, extends into the passage 18 of the cylinder block for a short distance inwardly of the point 19, this portion forming a tight fit with the passage 18 so as to securely hold the tube 22 in its position with the further aid of the mounting bracket 25.

The ullage rod 20, as seen in Figures 1, 3, and 4, is preferably composed of a continuous, elongated, normally straight strip or blade 26. By preference this strip is made of fiat or ribbon steel. It also preferably has round edges and is preferably of spring temper. The size of the strip depends somewhat upon the length of the ullage rod and the character of service to which it is to be sub jected. Where the rod must traverse one or more curved passages, it is essential that it have substantial flexibility so as to preferably return to its straight shape when removed from the engine. Thus for example, in actual practice where a long blade is required, a strip W wide and thick for insertion in a tube having a 7 inside diameter is satisfactory. Where a short blade is required for service in a substantially straight passage, a rod wide and A thick for insertion in a tube having a V inside diameter may be used. It may be noted that the round edges of the blade facilitate manipulation thereof in the tube 22 and also reduce nicking of the edge of the blade in handling.

As seen in Figure 3, the rod is formed adjacent its upper end with a series of undulations or crimps to provide a section 28 to fit the interior of the tube 22. Above the section 28 the rod has a fiat portion 30 to which is staked a hollow cup 32 which is receivable over the upper end 33 of the tube 22 and serves as a closure for the tube and stop for the rod 20. A felt washer 34 is positioned within the cup and seats against the end 33 of the tube to provide an oil and dust seal. The extreme upper end of the rod 20 above the cup 32 is formed with a loop or handle 36 which facilitates manipulation of the rod.

The strip or blade 26 is as previously stated preferably formed of flat flexible strip material which provides the opposite substantially fiat faces 40 and 42 respectively and the rounded edges 44 and 46 respectively. Projecting outwardly from the face 40 of the blade 26 adjacent the lower portion of the blade are oil smear inhibiting protuberances or upstanding portions 48 and 50 respectively, concerning whose function further reference will be made below. One of these upstanding portions 48 is located adjacent the extreme end 52 of the blade 26 at which position it will normally always be submerged in the oil of the reservoir 14 when the rod is in its normal position on the engine. The other upstanding portion 50 is located at a point more remote from the end 52 of the blade 26 and spaced from the upstanding portion 48, this location being such as to have this upstanding portion normally located just above the level 53 of the oil in the reservoir 14 when the engine has its full capacity of oil, but preferably is below the lower end of the passage 18 and tube 22 and within the reservoir 14.

As best seen in Figure 4, the upstanding portions or projections 48, 50 extend entirely across the face 40 of the blade 26 and have a dimension lengthwise of the strip approximately the width thereof such that these upstanding portions are of relatively narrow character. By preference the upstanding portions 48 and 50 may be formed by pressing or crimping the metal of the blade 26 outwardly of the plane thereof. In order to provide protection for the oil film on the reading surface under all expected conditions the projections should preferably extend from the reading face a distance at least the thickness of the blade. Moreover, the projections will preferably be formed with a curved surface which will facilitate camming of the blade over projections or corners intercepted in manipulating the rod to and from the engine.

Intermediate the projections 48 and 50 of the face 40 there is provided a level indicating area or face generally referred to by the numeral 54, and upon which is marked or inscribed as by stamping or otherwise suitable indicia' comprising level graduations, arrows and words of instruction. Thus there is preferably provided a transverse graduation 56 at a position below the projection 50 corresponding to the top level 53 of the oil in the reservoir 14 when the latter has its full complement of oil and is therefore stated to be full. An arrow 58 is positioned above the graduation 56 and points downwardly thereagainst to emphasize this position, and the word full appears at 60 immediately above the arrow 58.

A second transverse graduation or line 62 is located in the area 54 corresponding to the position registered on the blade 26 when the oil level in the reservoir 14 is down substantially, for example, one quart from full capacity. An arrow 64 points upwardly against the gradnation 62 to emphasize this position and immediately below the arrow 64 at the position 66 the words add oil appear to advise the operator of the need to keep the reservoir full of oil.

It will be observed that the projection 50 is located a greater distance above the full graduation mark 56 than the latter is spaced from the quart down graduation mark 62.

When testing the level of the oil in the reservoir 14, the rod 20 is withdrawn from the engine and the blade portion 26 wiped clean on a piece of cloth or waste. It is then inserted in the crankcase 12 through the tube 22 and passage 18 to the limit permitted by the cap 32. Since the blade 26 of the rod is normally straight, it will be necessary in the described arrangement for it to assume a bend or curve as it slides through the tube 22, its lower indicating portion again straightening as it emerges from the lower end of the tube 22 and passage 18. As the end of the blade 26 dips into the oil, it will be coated thereby to the depth of the oil in the reservoir 14 so that when the blade is withdrawn, a coating will appear on the rod extending from the tip 52 of the blade to a point in the indicating area 54 between the projections 48 and 50.

The blade is now withdrawn through the passage 18 in the cylinder block 12 and through the passage of the tube 22. In traversing these passages the projections 48, 50 will serve to keep the indicating face 54 of the blade away from the immediately juxtaposed inner wall of the passages 18 and 23 to thus prevent smearing of the oil film, produced on the immediate level indicating area of the blade 26 by the oil in the reservoir, by direct contact with the wall portions of the passages 18 and 23 or by contact of the stated oil film with oil wetted surface portions of the said passages which may intermingle with and effect a smudge of the said film to thereby render any reading of the oil level in the reservoir either inaccurate or impossible. Not only do the projections 48 and 50 serve this function as the blade is withdrawn through the straight passage 18, but their presence is particularly effective as the blade traverses the curved passage 23 of the tube 22. As seen in Figure 6, the projections 48 and 50 prevent the indicating portion 54 from coming into close chordal proximity to the transversely and longitudinally curved wall portion of the tube 22 to prevent any smearing of the oil film on this indicating area or interference therewith even though the blade 26 has been flexed to conform to the curvature of the tube 22. In this manner the oil level marking on the blade made by the oil film is preserved for reading when the rod is completely removed from the engine.

In certain cases where the receiving passage for the rod 22 in the engine is entirely straight, it is possible to substantially protect the indicating area by the use of a single projection 50. The use of both projections 48 and 50 is in these instances nevertheless recommended as the lower projection 48 is an added safety factor against smudging and moreover, aids in conjunction with the projection 50 to direct the eye of the person taking the oil reading to the indicating area 54 which as seen, occurs between the two projections.

In order to improve the ability of the reader to locate the upper edge of the oil film on the indicating area 54 of the ullage rod and thereby make an oil level reading, I preferably provide this area with a dull or preferably black-appearing surface. Thus, for example, the area 54, or if desired, the entire blade of the ullage rod may be treated with a chemical surface treatment which precipitates thereon a substantially dark or black-appearing coating or layer. This may, for example, be obtained by immersing the portion of the steel rod to be treated in a mixture of zinc phosphate and iron phosphate crystals dissolved in phosphoric acid. A chemical reaction takes place between the steel and the bath and produces on the surface of the steel a coating of Zinc iron phosphate which is substantially black in appearance. The black appearance of the surface may be further enhanced by subsequently re-treating the previously coated surface by immersing in a further bath made up of any soluble hydrocarbon oil to which has been added any black organic dye. By soluble oil I mean an oil emulsifiable in water.

The dark or black coating provided on the indicating surface of the ullage rod renders the oil film thereon, especially the edge limit of the oil film, more readily visible when the reading is taken.

From the aforesaid description it will be evident that I have provided an ullage rod which not only makes possible a clear and accurate reading of the oil level condition of an engine but which also permits of initially accurate readings by preventing the oil film obtained on the rod from the oil reservoir from being smeared or otherwise disturbed in removing the rod from the engine. It will be understood that various changes and modifications in the detailed structure of my ullage rod and coming within the spirit of my invention will occur to those skilled in the art and such changes and modifications are herein contemplated.

I claim:

1. In combination, in a motor vehicle structure having an oil-containing reservoir; an elongated tubular sheathing extending from a point externally of said structure to adjacent said reservoir, said sheathing providing a guide and protective passage for an ullage rod, and an ullage rod in said passage and extending into said reservoir, said rod having a substantially flat facial portion adjacent the lower end thereof, a pair of oil level indicating graduations on said facial portion representative of the full and a partially full capacity level respectively of the oil in said reservoir, a first smear inhibiting element projecting outwardly from said facial portion lengthwise of the ullage rod and above said full capacity graduation and below the end of said tube, and a second smear inhibiting element located below the said partially full indicating graduation.

2. The combination as claimed in claim 1 wherein said sheathing is curved lengthwise and said rod is provided with a closure member for closing the upper end of said sheathing and for providing a limit stop for the inward positioning of said rod in said sheathing and reservoir.

3. An oil level ullage rod for oil reservoirs of motor vehicles comprising an elongated blade having a substantially fiat facial portion adjacent the lower end thereof, an oil level indicating graduation on said facial portion representative of the oil level of the reservoir at its operably full capacity and a pair of spaced apart smear inhibiting elements on said facial portion projecting outwardly therefrom, one of said elements being located longitudinally of said blade adjacently above said full graduation and the other being located below the same.

4. An oil level ullage rod for oil reservoirs of motor vehicles comprising an elongated, flexible, substantially flat blade having adjacent one end thereof a pair of spaced apart smear inhibiting elements projecting outwardly from a face thereof and having oil level indicating graduations on said face intermediate said elements, at least one of said graduatlons being representative of the oil level of the reservoir at its operably full oil capacity. 5. An oil level ullage rod for oil reservoirs of motor vehicles comprising an elongated blade of substantially flat strip-like character, a pair of spaced apart smear inhibiting protuberances on a face of said blade and between the longitudinal edges thereof, said protuberances being integral with said blade and projecting above said face an amount at least the thickness of said blade, and oil level indicating graduations on said face intermediate said protuberances, one of said graduations being representative of the oil level of the reservoir at its operably full oil capacity.

6. An oil level ullage rod for oil reservoirs of motor vehicles comprising an elongated flexible substantially flat metallic blade having adjacent one end thereof a pair of spaced crimped portions forming smear inhibiting projections outwardly of one face of said blade, and having oil level indicating graduations on said face intermediate said projections, one of said graduations being representative of the oil level of the reservoir at its operably full oil capacity.

7. An oil level ullage rod for oil reservoirs of motor vehicles comprising an elongated flexible metallic blade having a longitudinally rounded smear inhibiting surface projection spaced from the lower end thereof, a substantially flat facial portion below said projection, an oil level indicating graduation on said facial portion, representative of the oil level of the reservoir at its operably full oil capacity, and a second smear inhibiting surface projection below said graduation and projecting in the same direction as said first mentioned projection.

8. An oil level ullage rod for oil reservoirs of motor vehicles comprising an elongated metallic blade of resil ient material, said blade having adjacent the lower tip end thereof a substantially fiat portion, said flat portion having spaced apart outwardly pressed longitudinally rounded portions forming prominent smear inhibiting projections thereon and having oil level indicating indicia on the same side of said flat portion as said projections and intermediate the same, said indicia comprising transverse graduations and longitudinally extending word markings denominating said graduations, one of said graduations being representative of the oil level of the reservoir at its operably full oil capacity.

9. An oil level ullage rod as claimed in claim 8 wherein said rod is made of steel and said flat portion containing said indicia includes a surface layer of zinc iron phosphate.

References Cited in the file of this patent UNITED STATES PATENTS 922,152 Kent May 18, 1909 1,421,672 Clarke July 4, 1922 1,574,267 Warner Feb. 23, 1926 2,314,915 Witchger Mar. 30, 1943 2,354,756 Keuffel et al. Aug. 1, 1944 2,550,897 Wilson May 1, 1951 2,552,330 Lamb May 8, 1951 FOREIGN PATENTS 194,560 Great Britain Mar. 15, 1923 

